Black tetrazo dye.



Nrrnn STATES PATENT OFFICE..-

JULIUS HERBABNY, OF OFFENBAOH-ON-TIIE-MAIN, AND CHRISTOPH IIARTMANN, OF FRANKFORT-ON-THE-MAIN, GERMANY.

BLACK TETRAZO DYE.

SPECIFICATION formingpart of Letters Patent No. 639,041, dated December 12, 1899.

Application filed September 28, 1898. Serial No. 692,075. ($peoimensi CH CH CH 1 2 A or meta phenylenediamin, respectively, with two molecules of para-nitro-diazobenzene, converting the thus-obtained tetra-amidodisazo body by sodium nitrite into a tetrazo compound, and, finally, combining the latter with two molecules of a suitable component.

The following example will illustrate the manner in which our invention may be carried out and brought into practical effect. The parts are, by weight:

Combine in a weakly soda-alkaline solution twelve and one-fifth (12.2) parts of toluylenediamin with twenty-seven and three-fifths (27.6) parts of paranitranilin diazolizedin the usual way with thirteen and four-fifths (13.8) parts of sodium nitrite. The precipitated dyestuff may either be isolated or directly reduced by sodium sulfid. In the latter case proceed as follows: mix sixty-three (63) parts of the dinitrodisazo dyestulf with one hundred and eighty (180) parts of sodium sulfid dismeta-diamin solved in eighty (80) parts of water and add, to quicken the reaction, two hundred and forty (240) parts of spirit and heat the whole to fifty to eighty degrees eentigrade to 80 C.) during four to six hours. The addition of spirit only serves to facilitate the reaction, and therefore is not absolutely necessary. After the reduction is finished distil off the spirit, dissolve the residue in diluted hydrochloric acid, filter, and precipitatewith alkalies. Then tetrazolize while cooling in hydrochloric-acid solution eighteen (18) parts of the obtained tetraamidodisazo compound with six and nine-tenths (6.9) parts of sodium nitrite and pour the whole into a solution of twenty-three and nine-tenths (23.9) parts of amidonaphtholsulfo-acid G, keeping alkaline by means of soda throughout the operation, and precipitate with common salt.

The dyestuff thus obtained forms a black powder with a metallic luster insoluble in cold, but easily soluble in hot water with a violet shade, which turns reddish on adding soda, whereas on adding acids the dyestuff falls down as a violet precipitate. Its solution in concentrated sulfuric acid is pure blue. "It dyes unmordanted cotton from acid or neutral baths deep black.

In the above example the meta-toluylenediamin may be replaced by the equivalent quantity of meta-phenylenediamin.

Now what we claim is As a new article of manufacture, the black coloring-matter which is obtained by combining the tetraamido disazo-dyestuif derived from a metadiamin of the benzene series and para-nitro diazo benzene chlorid with amidonaphtholsulfo-acid G, which has the general formula N:Npara-diaminN:N amidonaphtholsulfo-acid G N:N para-dialnin N:N amidon aphtholsulfo-acid G,

is a black powder with a metallic luster, in- I soluble in cold but easily soluble in hot water with a violet shade which turns reddish on addition of soda, forms a violet precipitate by the addition of acids to its aqueous solution, produces a pure-blue solution in concentrated sulfuric acid, and which dyes unmordanted cotton from alkaline or neutral baths a deep black which is very fast to washing, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

JULIUS I-IERBABNY. OHRISTOPH HAR'IMANN.

Witnesses:

DEAN B. MASON, JEAN GRUND. 

